Dylann Roof appears via video before a judge. (Centralized Bond Hearing Court/Associated Press)

IN AUTHORIZING the death-penalty prosecution of Dylann Roof, the white man accused of murdering nine people in a racially motivated assault at a historic African American church in Charleston, S.C., Attorney General Loretta E. Lynch cited the “nature of the alleged crime and the resulting harm.” There can be no disagreement about the merciless horror that occurred June 17, 2015, or about the evidence of Mr. Roof’s culpability. But we question whether justice is best served by pressing ahead with not one but two trials seeking the death penalty in the face of Mr. Roof’s offer to plead guilty in exchange for life in prison without possibility of release.

Some of the people whose lives were tragically touched by the events last year also question the government’s decision. The remarkable display of grace that characterized Charleston’s response to the shooting — including from family members of victims who publicly forgave the 21-year-old gunman days after the massacre — should cause federal and state prosecutors to rethink the wisdom of pressing ahead with costly trials and potentially protracted appeals that will cause the families and friends of victims to relive their trauma.

Mr. Roof is set to go on trial Nov. 7 on 33 federal charges in connection with the mass shooting at Emanuel African Methodist Episcopal Church. It will take an estimated two to three weeks to seat a jury and then two to three weeks for the trial and deliberations. Assuming a guilty verdict, there will be an additional three to four weeks as the jury decides the penalty. Then, in a jurisdictional pileup over the death penalty, South Carolina plans to go to trial with its own charges.

It seems senseless. Trials involving the death penalty are expensive; imprisoning Mr. Roof for life would cost taxpayers less. Studies show that death-penalty trials make it more difficult for survivors and relatives of victims to heal and recover. Three adults and two children survived the attacks; imagine what they might have to endure as these trials drag on through the end of the year.

“Racially motivated violence such as this is the original domestic terrorism,” Ms. Lynch said in explaining why the death penalty is appropriate. True. But some of the most powerful arguments against Mr. Roof’s execution are from prominent civil rights leaders. Wade Henderson, president and chief executive of the Leadership Conference on Civil and Human Rights, wrote a Post op-ed recalling the connection between the death penalty and racial discrimination that results in disproportionately more blacks being put to death. A poll by the University of South Carolina found a majority of black South Carolinians favor life without parole — not death — for Mr. Roof.

We urge Ms. Lynch to bring a speedy and final resolution to the federal case by accepting Mr. Roof’s guilty plea. The state should then drop its prosecution and let Mr. Roof be locked away for the rest of his sorry life.

Read more:

Wade Henderson: The pursuit of capital punishment for Dylann Roof is a step backward

Charles Lane: Why the muted response to seeking the death penalty for Dylann Roof?

Karen Attiah: Charleston, Dylann Roof and the racism of millennials

Kathleen Parker: A time to grieve for Charleston

George F. Will: Capital punishment’s slow death

Relatives of the nine victims killed in a shooting inside an AME church in Charleston, S.C., addressed the alleged shooter Dylann Roof during a bond hearing, many offering forgiveness to Roof. (Charleston County Government)